Post-exercise hypotension and its hemodynamic determinants depend on the calculation approach

Post-exercise hypotension (PEH) has been assessed by three calculation approaches: I = (post-exercise - pre-exercise), II = (post-exercise - post-control), and III = [(post-exercise - pre-exercise) - (post-control - pre-control)]. This study checked whether these calculation approaches influence PEH and its determinants. For that, 30 subjects underwent two exercise (cycling, 45 min, 50% VO₂ peak) and two control (seated rest, 45 min) sessions. Systolic (SBP) and diastolic (DBP) blood pressures, cardiac output (CO), systemic vascular resistance (SVR), heart rate (HR), and stroke volume (SV) were measured pre- and post-interventions in each session. The mean value for each moment in each type of session was calculated, and responses to exercise were analyzed with each approach (I, II, and III) to evaluate the occurrence of PEH and its determinants. Systolic PEH was significant when calculated by all approaches (I = -5 ± 1, II = -11 ± 2, and III = -11 ± 2 mmHg, p < 0.05), while diastolic PEH was only significant when calculated by approaches II and III (-6 ± 1 and -6 ± 1 mmHg, respectively, p < 0.05). CO decreased significantly after the exercise when calculated by approach I, but remained unchanged with approaches II and III, while SVR increased significantly with approach I, but decreased significantly with approaches II and III. HR was unchanged after the exercise with approach I, but increased significantly with approaches II and III, while SV decreased significantly with all approaches. Thus, PEH and its hemodynamic determinants are influenced by the calculation approach, which should be considered when designing, analyzing, and comparing PEH studies.